Method of making transparent quartz glass.



To all whom it may concern:

"cairn" METHOD OF MAKING TRANSPARENT QUARTZ GLASS.

No Drawing,

many, have invented a new and useful Method of Making Transparent Quartz Glass, of which-the following is a speci-fication. r

My invention relates to a method for making transparent quartz glass and has for its object utilization of arenaceous or ground quartz for this purpose.

The method consists in a non-transparent tube being primarily made of arenaceous or ground quartz in know n manner in an electric resistance furnace, whereupon said quartz tube is remolten and simultaneously drawn out man electric furnace and finallyagain molten in an ozryhydrogen flame or an electric arc and blown in known manner to molded articles.

The triple melting of the quartz material according to the present method is the reason, that finally ,articles of a transparent substance are obtained instead of the nontransparentor only translucent articles which are otherwise obtained from arenahigh price-of transparent quartz ceous or ground quartz.

As the principal part of the energy required is employed in form of electric energy in the electric furnace the present method has proven to be particularly economic compared with those methods which depended chiefly on the action of an o'xyhydrogen flame.

Owing to the low costs with which transparent quartz articles may be made accord ing to the present method, the latter renders it possible to manufacture all kinds of chemical utensils, water gages and also lamp glasses with advantage of quartz'material, what was hitherto. unadvisable owing to the and the fact that non-transparent or only translucent quartz material was useless for the said purposes.

In carrying out the present method one preferably will proceed in the following manner: First a non-transparent quartz cylinder is made in known manner in an i electric resistance furnace by embedding a heating rod in the space of said furnace, through which rod the electric current passes, in sand or ground quartz. The quartz charge in the furnace will then fuse Specification ofjLetters latent. Application filed February 18, 1911. Serial No. -609At5 'bles and the like.

around the rod and form a cylinder which may be blown out by introducing a gasifying substance and thereby forced into a mold, The thus obtained white, non-transparent cylinder is then'passed through a second electric tubular furnace which has a muti'le made of carbon and open in front and behind, in which muflie so high a temperature is produced by electric means that the non-transparent quartz tube will on being drawn through this furnace be re-molten. The quartz tube thus re-molten in the carbon tube is slowly drawn out to a thinner tube which is subsequently again remolten a third time in ox'yhydrogen flame or an electric arc and blown in the manner known in the glass blowers art to receivers, cruci The second fusion in the electric tubular furnace together with the simultaneous drawing out of the tube has the result, that the previously non-trans parent tube will become to a certain degree translucent sothat the subsequent-final fusion in the oxyhydrogen flame orthe electric arc will be able to produce a fully transparent material.

I desire it to I do not bind myself to the manner of carrying out the method as described above, but reserve to myself the right of varying or modifying it. For example the non-transparent quartz cylinder produced in the electric resistance furnace may not be first blown out in a mold by introducing a gasifying substance, but it may be drawn out to a smaller diameter during the passage through the carbon muffle of the second electric turnace, that is during the second fusion. The carbon rnuiiie has necessarily an inner diameter suiiiciently larger than the outer d1ameter of the quartz tube to permit an easy passage of the latter. The quartz tube remolten during the passage through the carbon muliie and thereby having become to a certain degree translucent may be-further drawn out to a thinner diameter or it may be finished during the passage through the oxyhydrogen flame or electric arc,' that is during the third fusion which renders the quartz transparent.

1" claim:

1. The herein described method of making transparent quartz electrically forming a now-transparent quartz tube from arenaceousquartz, ground quartz and the like, remelting and drawing out the,

be expressly understood, that IPaten-ted Jan. 1913.

articles, which consists in quartz tube so as to form a thinner tube, which is more or less translucent, and melting the translucent tube for a third time while finishing the article, whereby the quartz is rendered transparent.

2. The herein described method of making transparent quartz articles, which consists electrically forming a non-transparent quartz tube from arenaceous quartz, ground quartz and the like and immediately blowing out the quartz tube to form a hollow body, remeltlng and drawing out the quartz hollow body, whereby the quartz is rendered more and melting the translucent tube for a third time in a source of intense heat while finishingthe article, whereby the quartz is rendered transparent.

4. The herein described method of making transparent quartz articles, which consists in,

electrically forming a non-transparent quartz tube from arenaceous quartz, glOllllCl quartz and the like and immediately blowing outthe quartztube to form a. hollow body, electrically remelting and drawing-out the quartz hollow body, whereby the quartz is transparent quartz articles, which consists electrically forming a non-transparent qu a rendered more or less translucent, and melt inglthe trfinslucent drawn out body for a third time in a source of intense heat wt finishin the article, whereby the quartz; rendered transparent.

5. The herein described methodof maf body from arenaceous quartz, ground as and the like, electrical] reinelting a drawing out the quartz tu e so as to torn. thinner tube, which is more or less lucent, and melting the translucent tube t 1 a third time in an oxyhydrogen flame 'wh' finishin the article, whereby the quartz is rendered transparent.

6. The herein described method of matting transparentquartz articles, which consists in electrically forming a non-transpa:rent quartz tube from arenaceous quartz, ground quartz and the like and immediately blowing out the quartz tube to form a hollow body, electrically remelting and drawing; out the quartz hollow body, whereby the quartz rendered more or less translucent, ailcl'melting the translucent drawn out body for third time in an oxyhydrogen tiame while finishing the article, whereby the qiii-irtz is rendered transparent.

In testimony whereof I hereto t ll. 5 signature in the presence oi? two witnesses.

Nntonrius Mnuima, Louis VA NDORY. 

